What's the proper way to install pip, virtualenv, and distribute for Python?

Question

Short Question

• What is the proper way to install pip, virtualenv, and distribute?

Background

In my answer to SO question 4314376, I recommended using ez_setup so that you could then install pip and virtualenv as follows:

curl -O http://peak.telecommunity.com/dist/ez_setup.py
sudo python ez_setup.py
sudo easy_install pip
sudo pip install virtualenv

I originally pulled these instructions from Jesse Noller's blog post So you want to use Python on the Mac?. I like the idea of keeping a clean global site-packages directory, so the only other packages I install there are virtualenvwrapper and distribute. (I recently added distribute to my toolbox because of this Python public service announcement. To install these two packages, I used:

sudo pip install virtualenvwrapper
curl -O http://python-distribute.org/distribute_setup.py
sudo python distribute_setup.py

No more setuptools and easy_install

To really follow that Python public service announcement, on a fresh Python install, I would do the following:

curl -O http://python-distribute.org/distribute_setup.py
sudo python distribute_setup.py
sudo easy_install pip
sudo pip install virtualenv
sudo pip install virtualenvwrapper

Glyph's Rebuke

In a comment to my answer to SO question 4314376, SO user Glyph stated:

NO. NEVER EVER do sudo python setup.py install whatever. Write a ~/.pydistutils.cfg that puts your pip installation into ~/.local or something. Especially files named ez_setup.py tend to suck down newer versions of things like setuptools and easy_install, which can potentially break other things on your operating system.

Back to the short question

So Glyph's response leads me to my original question:

• What is the proper way to install pip, virtualenv, and distribute?

Answer 1

You can do this without installing anything into python itself.

You don't need sudo or any privileges.

You don't need to edit any files.

Install virtualenv into a bootstrap virtual environment. Use the that virtual environment to create more. Since virtualenv ships with pip and distribute, you get everything from one install.

1. Download virtualenv:
   • http://pypi.python.org/pypi/virtualenv
   • https://pypi.python.org/packages/source/v/virtualenv/virtualenv-12.0.7.tar.gz (or whatever is the latest version!)
2. Unpack the source tarball
3. Use the unpacked tarball to create a clean virtual environment. This virtual environment will be used to "bootstrap" others. All of your virtual environments will automatically contain pip and distribute.
4. Using pip, install virtualenv into that bootstrap environment.
5. Use that bootstrap environment to create more!

Here is an example in bash:

# Select current version of virtualenv:
VERSION=12.0.7
# Name your first "bootstrap" environment:
INITIAL_ENV=bootstrap
# Set to whatever python interpreter you want for your first environment:
PYTHON=$(which python)
URL_BASE=https://pypi.python.org/packages/source/v/virtualenv

# --- Real work starts here ---
curl -O $URL_BASE/virtualenv-$VERSION.tar.gz
tar xzf virtualenv-$VERSION.tar.gz
# Create the first "bootstrap" environment.
$PYTHON virtualenv-$VERSION/virtualenv.py $INITIAL_ENV
# Don't need this anymore.
rm -rf virtualenv-$VERSION
# Install virtualenv into the environment.
$INITIAL_ENV/bin/pip install virtualenv-$VERSION.tar.gz

Now you can use your "bootstrap" environment to create more:

# Create a second environment from the first:
$INITIAL_ENV/bin/virtualenv py-env1
# Create more:
$INITIAL_ENV/bin/virtualenv py-env2

Go nuts!

Note

This assumes you are not using a really old version of virtualenv. Old versions required the flags --no-site-packges (and depending on the version of Python, --distribute). Now you can create your bootstrap environment with just python virtualenv.py path-to-bootstrap or python3 virtualenv.py path-to-bootstrap.